1. Field of the Invention
This invention relates generally to object detection sensors on vehicles and, more particularly, to a method for performing a virtual alignment of short range radar or other sensors onboard a vehicle which detects a misalignment condition of one or more sensors, determines a calibration angle adjustment for the sensors, and performs a virtual calibration of the sensors by adjusting the sensor readings in software, without having to physically adjust the sensors.
2. Discussion of the Related Art
Many modern vehicles include object detection sensors, which are used to enable collision warning or avoidance and other active safety applications. The object detection sensors may use any of a number of detection technologies—including short range radar, cameras with image processing, laser or LIDAR, and ultrasound, for example. The object detection sensors detect vehicles and other objects in the path of the host vehicle, and the application software uses the object detection information to issue warnings or take actions as appropriate.
In order for the application software to perform optimally, the object detection sensors must be aligned properly with the vehicle. For example, if a sensor detects an object that is actually in the path of the host vehicle but, due to sensor misalignment, the sensor determines that the object is slightly to the left of the path of the host vehicle, this can have significant consequences for the application software. Even if there are multiple forward-looking object detection sensors on a vehicle, it is important that they are all aligned properly, so as to minimize or eliminate conflicting sensor readings.
In many vehicles, the object detection sensors are integrated directly into the front fascia of the vehicle. This type of installation is simple, effective, and aesthetically pleasing, but it has the disadvantage that there is no practical way to physically adjust the alignment of the sensors. Thus, if a sensor becomes misaligned with the vehicle's true heading, due to damage to the fascia or age- and weather-related warping, there has traditionally been no way to correct the misalignment, other than to replace the entire fascia assembly containing the sensors.